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S51-6 Basal ganglia circuitry: cognitive functions
29th International Congress of Clinical Neurophysiology
S73
S51-5 Long-term effects for deep brain stimulation for Parkinson’s disease
S52. NIRS application in clinical psychiatry
D.E. Vaillancourt1 , D. Corcos1 , M. Sturman1 , R. Bakay2 , L. Verhagen2 University of Illinois at Chicago, USA, 2 Rush University Medical Center, USA
S52-1 Approval of NIRS as the advanced medical technology in psychiatry
1
Objective: This lecture reports a study that examined the long-term effects of subthalamic nucleus (STN) deep brain stimulation (DBS) using both clinical and laboratory motor control measures. Methods: Over a five-year time period, changes in the motor section of the Unified Parkinson’s Disease Rating Scale (UPDRS) and bradykinesia and strength at the ankle joint were evaluated on and off stimulation in 8 patients with Parkinson’s disease (PD). Four patients were also studied at the elbow joint. PD patients originally received unilateral STN DBS between years 2001 and 2003 and were re-evaluated after 5 years of longterm STN DBS between years 2006 2008. At baseline and after 5 years, PD patients were tested off treatment (12 hour withdrawal of medication and stimulation) and on stimulation. In each testing condition patients performed ballistic, single degree of freedom ankle dorsiflexion and ankle plantarflexion movements and peak velocity was calculated. Patients also performed maximal voluntary contractions at the ankle joint in both directions, and peak torque was calculated. Results: Results showed increased motor UPDRS scores from baseline to Year 5, but STN DBS was efficacious in reducing them. The main novel finding was that motor control results showed a marked improvement in peak velocity and peak torque over the five year time period even in the off treatment condition. Discussion: The current findings suggest that STN DBS can have beneficial effects on the motor system over the long-term in discrete motor tasks in which maximal neural output is required. These findings are discussed in relation to different models of basal ganglia circuitry. S51-6 Basal ganglia circuitry: cognitive functions N. Sawamoto1 1 Human Brain Research Center, Kyoto University Graduate School of Medicine, Japan Patients with Parkinson’s disease (PD) show deficits when performing cognitive tasks such as mental operations and working memory paradigms, which engage frontal lobe regions. The deficits may reflect nigrostriatal dopaminergic degeneration resulting in disruption of the cortico-basal ganglia circuit, and/or mesocortical dopaminergic degeneration causing dysfunction of the frontal cortex. We investigated dopaminergic transmission during cognitive task performance by monitoring changes in synaptic dopamine levels by an in vivo D2 receptor marker 11 C-raclopride (RAC) with positron emission tomography (PET). In healthy subjects, RAC binding potential was significantly decreased during a working memory task compared with a motor control task, compatible with an increased level of dopamine transmission, in the striatum and medial prefrontal cortex. In mildly symptomatic patients with PD, RAC binding potential decrease during the working memory task was observed not in the striatum but in the medial prefrontal cortex. Our RAC PET study suggests that the capacity to release dopamine during working memory paradigm is impaired in the striatum but relatively preserved in the medial prefrontal cortex in mild PD patients. This pattern of dopamine release seems to be in accordance with our previous 15 O-H2 O PET findings showing hypoactivity of the striatum during a mental operation task in patients with PD. These PET findings support a view that nigrostriatal dopaminergic degeneration leading to disruption of the cortico-basal ganglia circuit is associated with the cognitive deficits observed in PD. The findings also imply that mesocortical dopaminergic function may be relatively preserved at least in mildly symptomatic patients with PD. Therefore, for dopamine replacement therapy the benefit to the striatum and the possible detrimental effects in the frontal cortex should be properly evaluated since excessive stimulation of dopamine receptors in the frontal cortex impairs its function.
M. Fukuda1 , M. Suda1 , Y. Takei1 , Y. Aoyama1 , T. Sato1 , N. Sakurai1 , K. Narita1 , M. Kameyama1 , T. Uehara2 , M. Mikuni1 1 Department of Psychiatry and Neuroscienece, Gunma University Graduate School of Medicine, Maebashi, Japan, 2 General Health Support Centre, Gunma University, Maebashi, Japan Objective: Near-infrared spectroscopy (NIRS) has been increasingly employed in psychiatry as functional neuroimaging researches of sleepiness [1], fatigue [2], personality [3,4], aging [5], brain activation time course [6], transcranial magnetic stimulation effects [7,8], and psychiatric disorders such as schizophrenia [9,10], mood disorders [9,11], panic disorder [12], and eating disorder [13,14]. NIRS is also can be employed practically as a clinical laboratory test for diagnosis and treatment of psychiatric disorders owing to its several advantages over other functional neuroimaging techniques. Methods: Characteristics of frontal lobe function were investigated using multichannel NIRS machines in unipolar depression, bipolar depression, and schizophrenia. Changes of oxygenated-hemoglobin concentration ([oxy-Hb]) were monitored every 0.1 s during a verbal fluency task using Hitachi ETG-4000 with the probes placed on the subjects’ frontal and temporal regions. Results: Characteristics of frontal lobe function were expressed as two parameters of [oxy-Hb] changes during the verbal fluency task: mean magnitude and latency of activation. Individual NIRS data can be plotted on the graph with these two parameters: unipolar depression is characterized by small magnitude and short latency, bipolar depression by large activation and long latency, and schizophrenia by small activation and long latency. Conclusion: NIRS has been officially approved as the first Advanced Medical Technology in psychiatry by Ministry of Health, Labour, and Welfare in Japan since 2009. Reference(s) [1] Neurosci Res 60:319, 2008. [2] Brain Res 1252:152, 2009. [3] Neuropsychobiology 52:45, 2005. [4] Neuropsychologia 48:441, 2010. [5] NeuroImage 22:1715, 2004. [6] Neurosci Res 58:297, 2007. [7] Neurosci Lett 414:99, 2007. [8] Neurosci Res 63:47, 2009. [9] Biol Psychiatry 55:501, 2004. [10] Schizophr Res 99:250, 2008. [11] NeuroImage 29:172, 2006. [12] Neurosci Res 59:107, 2007. [13] Eating Weight Disord 12:183, 2007. [14] J Psychiat Res 44:547, 2010. S52-2 Optical topography in attention deficit-/hyperactivity disorder A.J. Fallgatter1 1 Department of Psychiatry and Psychotherapy, University of T¨ ubingen, Germany Background: Like many psychiatric diseases attention-deficit/hyperactivity disorder (ADHD) is associated with alterations in brain function. This has been shown with multiple brain imaging approaches, in particular with functional Magnetic Resonance Imaging (fMRI). FMRI is undoubtly the imaging method with the best spatial resolution providing a neuroanatomical image of the brain within the same measurement. However, it’s setting and ecological validity is not optimal for patients with psychiatric illnesses. In particular the lying position, the fixation of the head, the extremely narrow surrounding and the loud EPI sequences are stressing for psychiatric patients and do definitely affect the results of fMRI studies. Methods: Near-Infrared Spectroscopy (NIRS) is suitable to elegantly measure concentration changes of oxygenated and deoxygenated hemoglobin in a more natural setting than fMRI with high ecological validity. Results: Studies with different perceptional, cognitive and emotional tasks proving test-retest reliability of NIRS in healthy subjects will be
S73
S51-5 Long-term effects for deep brain stimulation for Parkinson’s disease
S52. NIRS application in clinical psychiatry
D.E. Vaillancourt1 , D. Corcos1 , M. Sturman1 , R. Bakay2 , L. Verhagen2 University of Illinois at Chicago, USA, 2 Rush University Medical Center, USA
S52-1 Approval of NIRS as the advanced medical technology in psychiatry
1
Objective: This lecture reports a study that examined the long-term effects of subthalamic nucleus (STN) deep brain stimulation (DBS) using both clinical and laboratory motor control measures. Methods: Over a five-year time period, changes in the motor section of the Unified Parkinson’s Disease Rating Scale (UPDRS) and bradykinesia and strength at the ankle joint were evaluated on and off stimulation in 8 patients with Parkinson’s disease (PD). Four patients were also studied at the elbow joint. PD patients originally received unilateral STN DBS between years 2001 and 2003 and were re-evaluated after 5 years of longterm STN DBS between years 2006 2008. At baseline and after 5 years, PD patients were tested off treatment (12 hour withdrawal of medication and stimulation) and on stimulation. In each testing condition patients performed ballistic, single degree of freedom ankle dorsiflexion and ankle plantarflexion movements and peak velocity was calculated. Patients also performed maximal voluntary contractions at the ankle joint in both directions, and peak torque was calculated. Results: Results showed increased motor UPDRS scores from baseline to Year 5, but STN DBS was efficacious in reducing them. The main novel finding was that motor control results showed a marked improvement in peak velocity and peak torque over the five year time period even in the off treatment condition. Discussion: The current findings suggest that STN DBS can have beneficial effects on the motor system over the long-term in discrete motor tasks in which maximal neural output is required. These findings are discussed in relation to different models of basal ganglia circuitry. S51-6 Basal ganglia circuitry: cognitive functions N. Sawamoto1 1 Human Brain Research Center, Kyoto University Graduate School of Medicine, Japan Patients with Parkinson’s disease (PD) show deficits when performing cognitive tasks such as mental operations and working memory paradigms, which engage frontal lobe regions. The deficits may reflect nigrostriatal dopaminergic degeneration resulting in disruption of the cortico-basal ganglia circuit, and/or mesocortical dopaminergic degeneration causing dysfunction of the frontal cortex. We investigated dopaminergic transmission during cognitive task performance by monitoring changes in synaptic dopamine levels by an in vivo D2 receptor marker 11 C-raclopride (RAC) with positron emission tomography (PET). In healthy subjects, RAC binding potential was significantly decreased during a working memory task compared with a motor control task, compatible with an increased level of dopamine transmission, in the striatum and medial prefrontal cortex. In mildly symptomatic patients with PD, RAC binding potential decrease during the working memory task was observed not in the striatum but in the medial prefrontal cortex. Our RAC PET study suggests that the capacity to release dopamine during working memory paradigm is impaired in the striatum but relatively preserved in the medial prefrontal cortex in mild PD patients. This pattern of dopamine release seems to be in accordance with our previous 15 O-H2 O PET findings showing hypoactivity of the striatum during a mental operation task in patients with PD. These PET findings support a view that nigrostriatal dopaminergic degeneration leading to disruption of the cortico-basal ganglia circuit is associated with the cognitive deficits observed in PD. The findings also imply that mesocortical dopaminergic function may be relatively preserved at least in mildly symptomatic patients with PD. Therefore, for dopamine replacement therapy the benefit to the striatum and the possible detrimental effects in the frontal cortex should be properly evaluated since excessive stimulation of dopamine receptors in the frontal cortex impairs its function.
M. Fukuda1 , M. Suda1 , Y. Takei1 , Y. Aoyama1 , T. Sato1 , N. Sakurai1 , K. Narita1 , M. Kameyama1 , T. Uehara2 , M. Mikuni1 1 Department of Psychiatry and Neuroscienece, Gunma University Graduate School of Medicine, Maebashi, Japan, 2 General Health Support Centre, Gunma University, Maebashi, Japan Objective: Near-infrared spectroscopy (NIRS) has been increasingly employed in psychiatry as functional neuroimaging researches of sleepiness [1], fatigue [2], personality [3,4], aging [5], brain activation time course [6], transcranial magnetic stimulation effects [7,8], and psychiatric disorders such as schizophrenia [9,10], mood disorders [9,11], panic disorder [12], and eating disorder [13,14]. NIRS is also can be employed practically as a clinical laboratory test for diagnosis and treatment of psychiatric disorders owing to its several advantages over other functional neuroimaging techniques. Methods: Characteristics of frontal lobe function were investigated using multichannel NIRS machines in unipolar depression, bipolar depression, and schizophrenia. Changes of oxygenated-hemoglobin concentration ([oxy-Hb]) were monitored every 0.1 s during a verbal fluency task using Hitachi ETG-4000 with the probes placed on the subjects’ frontal and temporal regions. Results: Characteristics of frontal lobe function were expressed as two parameters of [oxy-Hb] changes during the verbal fluency task: mean magnitude and latency of activation. Individual NIRS data can be plotted on the graph with these two parameters: unipolar depression is characterized by small magnitude and short latency, bipolar depression by large activation and long latency, and schizophrenia by small activation and long latency. Conclusion: NIRS has been officially approved as the first Advanced Medical Technology in psychiatry by Ministry of Health, Labour, and Welfare in Japan since 2009. Reference(s) [1] Neurosci Res 60:319, 2008. [2] Brain Res 1252:152, 2009. [3] Neuropsychobiology 52:45, 2005. [4] Neuropsychologia 48:441, 2010. [5] NeuroImage 22:1715, 2004. [6] Neurosci Res 58:297, 2007. [7] Neurosci Lett 414:99, 2007. [8] Neurosci Res 63:47, 2009. [9] Biol Psychiatry 55:501, 2004. [10] Schizophr Res 99:250, 2008. [11] NeuroImage 29:172, 2006. [12] Neurosci Res 59:107, 2007. [13] Eating Weight Disord 12:183, 2007. [14] J Psychiat Res 44:547, 2010. S52-2 Optical topography in attention deficit-/hyperactivity disorder A.J. Fallgatter1 1 Department of Psychiatry and Psychotherapy, University of T¨ ubingen, Germany Background: Like many psychiatric diseases attention-deficit/hyperactivity disorder (ADHD) is associated with alterations in brain function. This has been shown with multiple brain imaging approaches, in particular with functional Magnetic Resonance Imaging (fMRI). FMRI is undoubtly the imaging method with the best spatial resolution providing a neuroanatomical image of the brain within the same measurement. However, it’s setting and ecological validity is not optimal for patients with psychiatric illnesses. In particular the lying position, the fixation of the head, the extremely narrow surrounding and the loud EPI sequences are stressing for psychiatric patients and do definitely affect the results of fMRI studies. Methods: Near-Infrared Spectroscopy (NIRS) is suitable to elegantly measure concentration changes of oxygenated and deoxygenated hemoglobin in a more natural setting than fMRI with high ecological validity. Results: Studies with different perceptional, cognitive and emotional tasks proving test-retest reliability of NIRS in healthy subjects will be